1. Field of the Invention
The present invention relates to an electrical connector, and more particularly to an electrical connector configured by upper and lower housings with contact terminals disposed therebetween. The contact terminals each includes a pair of legs secured in the lower housing, and a pair of hands extending into the upper housing.
2. Description of Related Art
Electrical connectors used to interconnect a central processing unit (CPU) to a printed circuit board (PCB) can be categorized into an Land Grid Array (LGA), a Ball Grid Array (BGA), and a Pin Grid Array (PGA).
An LGA-BGA connector disclosed in U.S. Pat. No. 7,074,048 which issued to Liao et al. on Jul. 11, 2006 includes an insulating housing having a plurality of passageways extending therethrough and a plurality of conductive terminals respectively received in the passageways of the insulating housing. Each terminal has a base portion, an elastic arm and a solder portion extending from opposite sides of the base portion, and a contacting portion located at a free end of the elastic arm. The solder portion has a solder ball attached thereon. The LGA-BGA connector establishes electrical connecting between the CPU and the PCB by reflowing the solder portions of the terminals to conductive pads of the PCB and the contacting between the contacting portions of the terminals and conductive pads of the CPU.
However, the height of the connector is increased by the structure of the terminals, so that the connector can not meet the development tread of low height.
U.S. Pat. No. 5,730,606 which issued to William on Mar. 24, 1998 discloses an electrical connector. The electrical connector includes an insulating housing having a plurality of passageways extending therethrough and a plurality of terminals received in corresponding passageways. Each terminal comprises a planar horizontal base portion having an upper surface and a lower surface opposite to each other, a pair of opposing arms and a pair of resilient opposing tangs extending upwardly from the upper surface of the base portion. The terminal has a fusible member attached to the lower surface thereof. The electrical connector establishes electrical connection between the CPU and the PCB through the arms of the terminals clamping solder balls of the CPU and soldering the terminals to the PCB by fusible members. However, the electrical connector need to predeterminately solder fusible members to the lower surfaces of the base portions, so as to increase costs and make process complex.
Another existing electrical connecting device comprises a printed circuit board (PCB) having a plurality of fusible members attached thereon and a central processing unit (CPU) with a plurality of solder balls. The electrical connecting device establishes electrical connection between the CPU and the PCB through the solder balls of the CPU being directly welded with the fusible members of the PCB. The electrical connecting device does not have an electrical connector located between the CPU and the PCB, so as to reduce the height of the electrical connecting device and make cost down. However, the CPU can be hardly removed in case of rework after the CPU is directly welded to the PCB.
In view of the above, an improved electrical connector for electrically connecting the CPU with the PCB is needed.